The Cisco CRS 8-slot line card chassis can be configured with either a DC-input power system or an AC-input power system. The chassis power system provides the necessary power for chassis components. Input power availability is site dependent and may be DC, AC Delta, or AC Wye.

A fixed configuration AC PDU connects to an AC rectifier, while a fixed configuration DC PDU connects to a DC PEM. A modular configuration AC power shelf houses up to 3 AC PMs, while a modular configuration DC power shelf houses up to 4 DC PMs. It is required that you use only one type of power shelf in a chassis at a time.

Note	In a modular configuration power system, both AC and DC power supplies are referred to as power modules (PMs).

Note	This unit might have more than one power module connection. All connections must be removed to de-energize the unit. Statement 1028

Three types of PDUs exist for fixed configuration power system:

• AC Wye PDU
• AC Delta PDU
• DC PDU

The AC PDU connects to the AC rectifier, while the DC PDU connects to the DC PEM. Although there are differences among the different PDU types (AC Wye, AC Delta, and DC), they are installed in the same manner.

Fixed configuration power system consists of two power distribution units (PDUs) and either DC power entry modules (PEMs) or AC rectifiers. The AC version requires 3-phase AC-Delta or AC-Wye input power to the PDU. The PDU distributes facility power to the AC rectifier or DC PEM, which in turn provides processed power to the chassis. The fixed configuration power system includes SNMP MIBS and XML support.

Note	In a fixed configuration AC or DC power system, PDU refers to the power component that connects to the AC rectifier or DC PEM.

For detailed information about AC and DC PDUs, see the Cisco CRS 3-Phase AC Power Distribution Unit Installation Guide .

Modular configuration power system consists of two power shelves and either AC or DC power modules (PMs). However, unlike the fixed configuration power system, the AC version of the modular configuration power system requires single-phase AC input power to power the shelves. If you have 3-phase AC-Delta or AC-Wye at your equipment, a Cisco CRS PDU will be required to convert 3-phase AC input power to single-phase AC input power for the power shelf. At the shelf level, the power system provides 2N redundancy; the PMs themselves provide load-share redundancy.

Note

In a modular configuration AC power system, PDU refers to the Cisco CRS PDU that converts 3-phase AC-Wye or AC-Delta input power to single-phase AC input power for the modular configuration AC power shelf. For further information, refer to Cisco CRS 3-Phase AC Power Distribution Unit Installation Guide.

Caution

Use only one type of modular configuration power shelf—AC or DC—and its mating AC or DC PMs in a chassis at one time.

Follow these precautions and recommendations when planning power connections to the router:

• For the fixed configuration power system, although PDUs may be installed or removed without powering down the system, for safety purposes we recommend that you power down the system before you install or remove a PDU.
• For the modular configuration power system, although power shelves may be installed or removed without powering down the system, for safety purposes we recommend that you power down the system before you install or remove a power shelf.

The router chassis has safety earth ground connections in conjunction with the power cabling to the fixed configuration PDUs. Modular configuration supports chassis grounding only. The chassis allows you to connect the central office ground system or interior equipment ground system to the bonding and grounding receptacles on the router chassis, when either a fixed or modular configuration power system is installed.

Each side of the chassis has one pair of threaded ground studs located on the inside of the chassis and two sets of grounding receptacles located on the outside of the chassis. These ground points are also called the network equipment building system (NEBS) bonding and grounding points.

Note	These bonding and grounding receptacles satisfy the Telcordia NEBS requirements for bonding and grounding connections.

This figure shows six chassis grounding points that are provided at the rear (MSC) side of the chassis.

Caution

Do not remove the chassis ground wire unless the chassis is being replaced.

See the Cisco CRS Carrier Routing System 8-Slot Line Card Chassis Installation Guide for additional grounding and bonding details and installation instructions.

Each DC powered chassis contains two fixed configuration PDUs or two modular configuration power shelves for 2N redundancy.

• In the fixed configuration power system, each PDU accepts one DC PEM for 2N redundancy. The PDUs and PEMs are field replaceable. The PDUs contain the input power connectors.
• In the modular configuration power system, each power shelf accepts up to four PMs. The power shelves and PMs are field replaceable. The power shelves contain the input power connectors.

Note	Depending on the hardware deployed at your site, your system may not consume the maximum power supplied by the power system.

Each AC powered chassis contains two AC power shelves for 2N redundancy. The shelves contain the input power connectors.

• In the fixed configuration power system, each PDU accepts one AC power rectifier. The PDUs and AC power rectifiers are field replaceable.
• In the modular configuration power system, each power shelf can contain up to three AC PMs. The power shelves and the AC PMs are field replaceable. See Modular Configuration Power System.

Note	Depending on the hardware deployed at your site, your system may not consume the maximum power supplied by the power system.

This section describes the Cisco CRS 8-slot fixed power configuration system.

Caution

Use only one type of fixed configuration PDU—AC Wye, AC Delta, or DC—and its mating AC rectifier or DC PEM in a chassis at one time.

The Cisco CRS 8-slot line card chassis DC power system provides 7,500 watts to power the chassis. Each DC PDU is connected to three pairs of DC power feeds and powers a single DC PEM. Input DC power enters the PDU and is passed to the PEM, which provides power to the components in the chassis.

• Each DC PEM has its own circuit breaker.
• The fixed configuration power system distributes power in power zones.
• The DC PDUs and DC PEMs are field replaceable.

Cisco CRS 8-Slot chassis AC and DC fixed configuration power systems use A and B power supplies to provide reliable power to all chassis components. In the fixed configuration power system, each PDU accepts one DC PEM for 2N redundancy. The PDUs and PEMs are field replaceable. The PDUs contain the input power connectors.

The chassis requires 8.0 kW of DC input power and 8.75 kW of AC input power from the building supply.

AC or DC input power enters the chassis through the A and B power supplies and is distributed to the A or B power bus. Both buses distribute power through the midplane to the MSC, PLIM, switch fabric, and RP card slots. See the figure titled CRS 8-Slot Line Card Chassis Power Distribution - Fixed DC Configuration in the Fixed Configuration DC Power Distribution Unit section for the 8-slot chassis power routing distribution for a fixed DC configuration and the figure titled CRS 8-Slot Chassis AC Delta Power Distribution - Fixed Configuration in the Fixed Configuration AC Delta Power section for the power routing distribution for a fixed AC configuration.

• The A power module supplies –54.5 VDC to the A bus.
• The B power module supplies –54.5 VDC to the B bus.

Because chassis components are powered by both A and B power inputs, the line card chassis can continue to operate normally if:

• One AC rectifier or DC PEM fails.
• One input power (A or B) fails.
• One bus fails.
• One PDU fails.

It takes two failures for the system to be degraded. In addition, the failures must occur in both the A and B sides of the power architecture and affect the same power zone for the degradation to occur.

Individual chassis components have power-related devices (OR-ing diodes, inrush control circuits, and EMI filters) that are part of the chassis power architecture. These power-related devices form part of the dual power source (A and B bus) architecture, and enable online insertion and removal (OIR) of the components, also called hot swapping .

The AC or DC power system distributes power in the chassis through three power zones, which provide power redundancy and reliability. Each power zone receives power from both power supplies, which ensures that each zone can operate in case of one power module failure.

This image shows the three power zones in the chassis. The table below the figure identifies the power redundancy connection for the fan trays.

The zones shown in Figure 1 are further explained in Table 1 and Table 2.

Each fan tray—the upper fan tray (Fan 0) or the lower fan tray (Fan 1)—is powered by both PS A and PS B to have power redundancy for the fan tray. In addition, both fan trays receive power from both Power Zones 1 and 3 for redundancy. Both fan trays are monitored by RP0 and RP1 shelf controllers.

Any types of cards can be installed in a power zone.

The Cisco CRS 8-slot line card chassis DC power system provides 7,500 watts to power the chassis. Each DC PDU is connected to three pairs of DC power feeds and powers a single DC PEM. Input DC power enters the PDU and is passed to the PEM, which provides power to the components in the chassis.

• Each DC PEM has its own circuit breaker.
• The fixed configuration power system distributes power in power zones.
• The DC PDUs and DC PEMs are field replaceable.

Unlike the Cisco CRS 16-slot line card chassis, the Cisco CRS 8-slot line card chassis does not contain an alarm module. A microprocessor in the DC PEM monitors the status of each DC PEM. The microprocessor communicates with the system controller on the route processor (RP) card. LEDs on the front panel of the RP card indicate active alarm conditions.

The DC PDU is shipped with a plastic safety cover over the input terminal block, as shown in the figure below. This safety cover has two parts, each part held on to the PDU with a Phillips screw. We recommend removing the safety cover only when wiring and unwiring the chassis. The safety cover is slotted in such a way that the wires can only come out on the bottom portion of the cover.

Each PDU requires three DC inputs of –48/–60 VDC (nominal), 60 A service. The PDU accepts input DC power in the range –40.5 to –75 VDC, and has three sets of double-stud terminals (-48/-60 VDC Lines and -48/-60 VDC Returns) for connecting to the VDC inputs.

Each DC PDU should be connected to a different central office DC power source:

• One PDU should be connected to three –48/–60 VDC “A” buses.
• Other PDU should be connected to three –48/–60 VDC “B” buses.

If DC power to a PDU fails, the other PDU provides enough power for the chassis. This 2N power redundancy enables the routing system to operate in spite of single power failure.

For DC power cables, we recommend that you use commensurately rated, high-strand-count copper wire cable, based on local electrical codes. These wires are not available from Cisco Systems; they are available from any commercial vendor. DC power cables must be terminated by cable lugs at the power shelf end.

This table lists the fixed configuration DC power components and PIDs for the Cisco CRS 8-Slot Line Card Chassis.

An AC-powered Cisco CRS 8-slot line card chassis contains two AC power distribution units (PDUs) and two AC rectifier modules. Each AC PDU is connected to a 3-phase (200 to 240) input VAC power source and connects to a single 7500-watt AC rectifier module that is field replaceable. Each AC rectifier module converts input AC power to the 54.5 VDC used by the chassis. Each rectifier has its own circuit breaker.

To provide 2N power redundancy for the chassis, each PDU and AC rectifier pair is connected to a different AC power source. During normal operation when both power sources are operational, both PDUs and rectifiers function together to power the chassis. However, if a power source fails, the other power source provides the other PDU and rectifier pair with enough input power to power the chassis. This 2N power redundancy enables the routing system to operate despite the power failure.

Two versions of the AC PDU are available to accommodate AC input power in either the Delta or Wye (see Figure 1 for fixed AC Wye PDU) configuration. Each PDU has a different Cisco part number. The PDUs are shipped with AC power cords that are 14 feet (4.3 m) long.

Unlike the Cisco CRS 16-slot line card chassis, the Cisco CRS 8-slot line card chassis does not contain an alarm module. A microprocessor in the AC rectifier monitors the status of each AC rectifier. The microprocessor communicates with the system controller on the RP card. LEDs on the front panel of the RP card indicate active alarm conditions.

The AC PDUs have the following input VAC power requirements:

• AC Wye input: 3-phase, 200 to 240 VAC nominal (phase-to-neutral), 50 to 60 Hz, 16 A (International) or 20 A (North America). The PDU is rated for 14-amp service, and accepts AC input of 16 or 20 A.

The Wye power cord has a 5-pin IEC 60309 plug that is rated for 400 VAC, 16 or 20 A, (3W + N + PE). The power cord plugs into a similarly rated IEC 60309 receptacle.

• AC Delta input: 3-phase, 200 to 240 VAC nominal (phase-to-phase), 50 to 60 Hz, 30 A. The PDU is rated for 24-amp service, and accepts AC input of 30 A.

The Delta power cord has a 4-pin NEMA L15-30P plug that is rated for 250 VAC, 30 A (3W + PE). The power cord plugs into a similarly rated NEMA L15-30R locking-type receptacle.

This table lists the AC power components and PIDs for the Cisco CRS 8-Slot Line Card Chassis.

Note	For a complete list of CRS 8-slot chassis power specifications, see Appendix 1, “Technical Specifications.”

This section describes the CRS 8-slot chassis modular configuration power system. The modular configuration power solution is configurable. It includes the following components:

• Two (redundant) AC or DC power shelves
• Up to three AC power modules or four DC power modules per power shelf
• Each DC power module provides 2100 Watts, with potential growth up to 8.4KW DC power per power shelf
• Each AC power module provides 3000 Watts, with potential growth up to 9KW DC power per power shelf

Note	The default modular configuration power system may not ship with the maximum number of power modules configured. Additional power modules can be added at any time, depending on the system’s power requirements.

The figures show an AC modular power module for the Cisco CRS 8-slot chassis.

The figures show a front and rear view of a DC modular power shelf for the Cisco CRS 8-slot chassis.

In the modular configuration power system, each power shelf accepts up to four PMs. The power shelves and PMs are field replaceable. The power shelves contain the input power connectors.

Note	Depending on the hardware deployed at your site, your system may not consume the maximum power supplied by the power system.

The modular configuration power module provides the following features:

• AC or DC power shelf redundancy
• PM load-share redundancy
• Elimination of power zone restriction, while maintaining zone protection
• Capacity for future growth

The modular AC and DC power systems use A and B power shelves to provide reliable, 2N redundant power to all chassis components.

All power modules in the modular power shelf power all zones. In addition, the modular power supplies work in parallel with each other, and they can monitor power consumption, performance, analysis, and power management concurrently.

Unlike the Cisco CRS 16-slot line card chassis, the power shelf on the Cisco CRS 8-slot line card chassis does not contain an alarm module. Instead, alarm functionality is integrated into the Route Processor (RP). The DC power module monitors power module status and processes alarm functions. The AC or DC power module distributes power and passes power module status signals to the system. Each power module has its own integrated fuse to protect the system, and each power module is plugged into its own power outlet.

The Cisco CRS 8-Slot Line Card Chassis requires 8.0 kW of DC input power and 8.75 kW of AC input power from the building supply.

The Cisco CRS 8-slot line card chassis modular configuration DC power system can provide up to 8,400 W to power the line card chassis. The modular configuration DC power system uses A and B power shelves to provide reliable, 2N redundant power to all chassis components.

Note	Depending on the hardware deployed at your site, your system may not consume the maximum power supplied by the power system.

If DC power to one modular configuration power shelf fails, the other power shelf provides enough power for the chassis. This 2N power redundancy enables the routing system to operate in spite of single power failure.

This table summarizes the DC power system specifications for the Cisco CRS 8-Slot Line Card Chassis.

This figure shows the 8-slot chassis power routing distribution for a modular DC configuration.

The Cisco CRS 8-slot line card chassis modular configuration AC power system can provide up to 9,000 W to power the line card chassis.

Note	Depending on the hardware deployed at your site, your system may not consume the maximum power supplied by the power system.

The modular configuration power system provides the following features:

• AC power shelf redundancy
• PM load-share redundancy
• Elimination of power zone distribution, while maintaining zone protection
• Capacity for future growth

The modular configuration AC power systems use A and B power shelves to provide reliable, 2N redundant power to all chassis components.

The Cisco CRS 8-slot line card chassis does not contain an alarm module. The AC PM monitors PM status and processes alarm functions. The AC PM distributes power and passes PM status signals to the system. Each PM has its own integrated fuse to protect the system, and each PM is plugged into its own power outlet. Alarms are processed through the RP. LEDs on the front panel of the RP indicate active alarm conditions.

Unlike the fixed configuration AC power system, which requires 3-phase AC Delta or AC Wye input power, the modular configuration AC power system requires single-phase AC input power. If you have 3-phase AC Delta or AC Wye at your equipment, a Cisco CRS PDU will be required to convert 3-phase AC input power to single-phase AC input power for the power shelf .

This figure shows the power routing distribution of the 8-slot chassis with a modular AC configuration power system.

As shown in the figure, AC input power enters the chassis through the A and B power supplies and is distributed to the A or B power bus. Both buses distribute power through the midplane to the MSC, PLIM, switch fabric, and RP card slots.

Each DC power module provides 2 voltages:

• Output voltage 1 is –54 VDC
• Output voltage 2 is +5Vaux

Because chassis components are powered by both A and B power inputs, the line card chassis can continue to operate normally if:

• One AC or DC power module fails
• One input power (A or B) fails
• One internal bus bar fails
• One entire power shelf fails
• Power modules are added to, or removed from the power shelf

Because no exact redundancy exists across the power modules, individual power modules can be removed without causing the chassis to lose power.

Individual chassis components have power-related devices, such as OR-ing diodes, inrush control circuits, and EMI filters. Because any power modules can power all chassis components, these devices can be inserted or removed (OIR) while the chassis is online. This component insertion and removal is also called hot-swapping .

The modular configuration AC power shelf has the following input VAC power requirements:

• Single-phase, 200 to 240 VAC nominal, 50 to 60 Hz, 16 A
• Each power shelf contains three IEC-320-C22 receptacles which can accept up to three IEC-320-C21 connector female plugs, depending on how many AC PMs are installed in the shelf.

Note	In order to maintain a balanced 3-phase power load, three AC PMs are required to be installed in a Cisco CRS 8-slot line card chassis AC modular configuration power shelf.